The embodiment relates to a wireless power transmitter, a wireless power receiver, a wireless power transmission method and a wireless power reception method. In more particular, the embodiment relates to a wireless power transmission for actively transmitting power according to power transmission state between a wireless power transmitter and a wireless power receiver.
A wireless power transmission or a wireless energy transfer refers to a technology for wirelessly transferring electric energy to desired devices. In the 1800's, an electric motor or a transformer employing the principle of electromagnetic induction has been extensively used and then a method for transmitting electric energy by irradiating electromagnetic waves, such as radio waves or lasers, has been suggested. Actually, electric toothbrushes or electric razors, which are frequently used in daily life, are charged based on the principle of electromagnetic induction. Until now, the long-distance transmission using the magnetic induction, the resonance and the short-wavelength radio frequency has been used as the wireless energy transfer scheme.
However, according to the related art, power transmission environment between a transmission side and a reception side cannot be actively recognized upon the wireless power transmission between the transmission side and the reception side. Thus, a bidirectional communication for sharing state information between the transmission side and the reception side is necessary to achieve more effective and active power transmission.